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5 tháng 10 2015

\(\frac{2x}{3}=\frac{5}{7}\Rightarrow2x.7=3.5\)

\(\frac{2x.7}{14}=\frac{3.5}{14}\)

\(x=\frac{3.5}{14}\)

\(\Rightarrow x=\frac{15}{14}\)

27 tháng 12 2019

\(\frac{-2}{1,5}=\frac{-2.2}{1,5.2}=\frac{-4}{3}=\frac{x-1}{3}\)

\(\Rightarrow x-1=-4\)\(\Rightarrow x=-3\)

Vậy \(x=-3\)

27 tháng 12 2019
-2/1,5=x-1/3 =>(-2)×3=1,5×(x-1) =>-6=1,5x-1,5 1,5x=-6+1,5=-4,5 x=-4,5÷1,5 x=-3 Vậy x=-3
19 tháng 8 2019

Lời giải :

Do \(VT\ge0\forall x;y\)nên ta có hệ :

\(\hept{\begin{cases}\frac{2}{3}-\frac{1}{2}+\frac{3}{4}x=0\\1,5-\frac{11}{17}+\frac{23}{13}y=0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x=\frac{-2}{9}\\y=\frac{-377}{782}\end{cases}}\)

Vậy...

18 tháng 8 2020

a) \(\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)

=> \(\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}\)

=> \(\frac{2}{3}x=-\frac{29}{70}\)

=> \(x=-\frac{29}{70}:\frac{2}{3}\)

=> \(x=-\frac{29}{70}.\frac{3}{2}\)

=> \(x=-\frac{87}{140}\)

b) \(-\frac{21}{13}x+\frac{1}{3}=-\frac{2}{3}\)

=> \(-\frac{21}{13}x=-\frac{2}{3}-\frac{1}{3}\)

=> \(-\frac{21}{13}x=-\frac{3}{3}\)

=> \(-\frac{21}{13}x=1\)

=> \(x=1:\left(-\frac{21}{13}\right)\)

=> \(x=-\frac{13}{21}\)

c) \(\left|x-1,5\right|=2\)

=> \(\left[{}\begin{matrix}x-1,5=2\\x-1,5=-2\end{matrix}\right.=>\left[{}\begin{matrix}x=2+1,5\\x=-2+1,5\end{matrix}\right.\)

=> \(\left[{}\begin{matrix}x=3,5\\x=-0,5\end{matrix}\right.=>\left[{}\begin{matrix}x=\frac{7}{2}\\x=-\frac{1}{2}\end{matrix}\right.\)(T/M)

d) \(\left|x+\frac{3}{4}\right|-\frac{1}{2}=0\)

=> \(\left|x+\frac{3}{4}\right|=\frac{1}{2}\)

=> \(=>\left[{}\begin{matrix}x+\frac{3}{4}=\frac{1}{2}\\x+\frac{3}{4}=-\frac{1}{2}\end{matrix}\right.=>\left[{}\begin{matrix}x=\frac{1}{2}-\frac{3}{4}\\x=-\frac{1}{2}-\frac{3}{4}\end{matrix}\right.=>\left[{}\begin{matrix}x=-\frac{1}{4}\\x=-\frac{5}{4}\end{matrix}\right.\)(T/M)

HỌC TỐT vui

18 tháng 8 2020

a) \(\frac{2}{3}x+\frac{5}{7}=\frac{3}{10}\)

\(\Leftrightarrow\frac{2}{3}x=\frac{3}{10}-\frac{5}{7}\)

\(\Leftrightarrow\frac{2}{3}x=-\frac{29}{70}\)

\(\Leftrightarrow x=-\frac{29}{70}:\frac{2}{3}\)

\(\Leftrightarrow x=-\frac{87}{140}\)

b) \(-\frac{21}{13}x+\frac{1}{3}=-\frac{2}{3}\)

\(\Leftrightarrow-\frac{21}{13}x=-\frac{2}{3}-\frac{1}{3}\)

\(\Leftrightarrow-\frac{21}{13}x=-1\)

\(\Leftrightarrow x=-1:\left(-\frac{21}{13}\right)\)

\(\Leftrightarrow x=\frac{13}{21}\)

c) \(\left|x-1,5\right|=2\)

\(\Leftrightarrow\left[{}\begin{matrix}x-1,5=2\\x-1,5=-2\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=3,5\\x=-0,5\end{matrix}\right.\)

d) \(\left|x+\frac{3}{4}\right|-\frac{1}{2}=0\)

\(\Leftrightarrow\left|x+\frac{3}{4}\right|=\frac{1}{2}\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\frac{3}{4}=\frac{1}{2}\\x+\frac{3}{4}=-\frac{1}{2}\end{matrix}\right.\) \(\Leftrightarrow\left[{}\begin{matrix}x=-\frac{1}{4}\\x=\frac{5}{4}\end{matrix}\right.\)

6 tháng 9 2018

lên mạng mà tìm đúng cho tui đi

6 tháng 9 2018

\(1,5.x-1,5=\frac{5}{3}-x\)

\(1,5.x+x=\frac{5}{3}+1,5\)

\(2,5.x=\frac{19}{6}\)

\(x=\frac{19}{6}:2,5\)

\(x=\frac{19}{15}\)

\(a,\frac{3}{4}+\frac{1}{4}:x=\frac{2}{5}\)

\(\Leftrightarrow\frac{1}{4}:x=\frac{2}{5}-\frac{3}{4}\)

\(\Leftrightarrow\frac{1}{4}:x=\frac{8}{20}-\frac{15}{20}\)

\(\Leftrightarrow\frac{1}{4}:x=\frac{-7}{20}\)

\(\Leftrightarrow x=\frac{1}{4}.\frac{20}{-7}\)

\(\Leftrightarrow x=\frac{20}{-28}\)

\(b,|x-2,5|=1,5\)

\(\Leftrightarrow\orbr{\begin{cases}x-2,5=1,5\\x-2,5=-1,5\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=1,5+2,5\\x=-1,5+2,5\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=3\\x=1\end{cases}}\)

\(\frac{\left(x+1\right)}{1,5}=\frac{3}{2\left(x+1\right)}\)

\(\Leftrightarrow\left(x+1\right).2\left(x+1\right)=1,5.3\)

\(\Leftrightarrow\left(x+1\right).2x+2=\frac{9}{2}\)

\(\Leftrightarrow\orbr{\begin{cases}x+1=\frac{9}{2}\\2x+2=\frac{9}{2}\end{cases}\Leftrightarrow\orbr{\begin{cases}x=\frac{7}{2}\\2x=\frac{5}{2}\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{7}{2}\\x=\frac{5}{4}\end{cases}}}\)

29 tháng 2 2020

\(\frac{x+1}{1,5}=\frac{3}{2\left(x+1\right)}\)

\(\Rightarrow2\left(x+1\right)^2=4,5\)

\(\Rightarrow\left(x+1\right)^2=\frac{9}{4}\)

\(\Rightarrow\orbr{\begin{cases}x+1=\sqrt{\frac{9}{4}}\\x+1=-\sqrt{\frac{9}{4}}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{1}{2}\\x=-\frac{5}{2}\end{cases}}\)

10 tháng 4 2017

\(\frac{2}{3}-1\frac{4}{15}x=\frac{-3}{5}\)

           \(1\frac{4}{15}x=\frac{19}{15}\)

                    \(x=1\)

- 2 3 + 0,5 x = 1,5

   - 8 + 0,5 x = 1,5

           0,5 x = 9,5

                 x = 19